1. Field of Invention
The present invention relates to a small-sized hydroelectric power generating apparatus using water power generated by flow of water passing through a faucet.
2. Related Art
Conventional, an automatic water faucet apparatus is known well, in which by detecting by a sensor that a user holds out his hand beneath a faucet, water flows from the faucet. Further, recently, an apparatus is also proposed, in which a small-sized power generating apparatus is provided at a fluid passage of such the automatic water faucet apparatus, and the consumption power of a circuit of the afore-mentioned sensor is supplied by storing the electric power obtained by this small-sized power generating apparatus (refer to Unexamined Japanese Utility Model Publication Hei. 2-65775).
The constitution of the afore-mentioned small-sized hydroelectric power generating apparatus will be briefly described below. A water wheel is provided at a fluid passage used as a passage of flowing water, and this water wheel rotates upon reception of water power of the flowing water. For a rotational shaft of the water wheel, a rotator integrally fixed to the shaft is provided. The outer surface of this rotator becomes a magnetized rotor magnet, and this rotor magnetic is arranged opposed to pole teeth of a stator portion with a wall of non-magnetic member between. Further, for this stator portion, a stator coil is provided so as to interlink to magnetic fluxes passing the pole tooth. And, the above-mentioned water wheel rotates upon reception of the water power of the flowing water, whereby the rotor magnetic rotates relatively in relation to the stator portion. Since the rotor is magnetized multipolar, change is produced in flow of the magnetic fluxes flowing in the stator portion. As a result, an electromotive force is produced in the stator coil in a direction where the change in the flow of the magnetic fluxes can be prevented. After this electromotive force was rectified, it is stored in a storage battery.
As described above, the small-sized hydroelectric power generating apparatus is so constructed that the water wheel receives the water power of the flowing water, whereby the multipolar magnetized rotor magnet rotates together with the water wheel. By the way, between this rotor magnet and the pole tooth arranged outside of the magnet so as to be opposed to the magnet, detent torque is produced. This detent torque gives resistance to rotation of the water wheel. Therefore, such a problem is produced that the water wheel does not rotate smoothly, or the water wheel does not rotate at all if the amount of the flowing water is a little. If the gap between the rotor magnet and the pole tooth is expanded, the detent torque is reduced, so that the afore-mentioned problem can be prevented. However, the effective magnetic fluxes necessary to generate the electric power are also reduced together. Accordingly, if the gap between them is made wider than it needs, the electric power cannot be generated effectively. From this reason, in this type of small-sized hydroelectric power generating apparatus, such a proposition that power generation is performed efficiently with a smaller amount of flowing water cannot be solved.
Further, the above-mention small-sized hydroelectric power generating apparatus is so constructed that a water wheel is surrounded with a wall, and an ejection hole for ejecting water to vane portions of the water wheel is formed in this wall. This ejection hole is used in order to rotate the water wheel efficiently by suitably throttling the amount of the water entering from an inlet. It is important to improve the rotational efficiency of the water wheel since it connects to the improvement of the power generation efficiency of the electric power generating apparatus. In order to improve the ejection efficiency of water, it is necessary to calculate more accurately positional accuracy between the ejection hole and the vane portion of the water wheel, an angle of the ejection hole to the water wheel, a hole diameter, a shape of the wall having the ejection hole, a shape of a fluid passage outside of the wall, and to perform a high level of machining.
In consideration of the rotational efficiency of the water wheel, it is preferable that the number of the above-mentioned ejection holes is three, four, or more. In addition, the ejection hole is orthogonally opposed to the vane of the water wheel, which contributes to improvement of the rotational efficiency of the water wheel. However, in case that the number of the ejection holes is three or more, and the ejection hole is not opposed to the central axis but orthogonally opposed to the vane, machining is very complicated and expensive. Namely, it is because it is necessary to increase the number of molds at the machining time of the wall according to the number of the ejection holes and facing (angle) of the hole or to turn-separate the mold at the mold separation time.
Accordingly, in the conventional cases, a water wheel that is cheap in a molding cost is selected rather than the rotational efficiency of the water wheel. Namely, so that the apparatus can be molded with a two-divided and simple two-directional separation mold, the number of the above-mentioned ejection holes is set to two or one, and the angle of each ejection hole to the water wheel is frequently set to a range where machining can be performed with a simple bi-directional separation mold. Namely, in the conventional small-sized hydroelectric power generating apparatus, generally, about two ejection holes were formed in the surrounding wall of the water wheel, and there ware not many ideas for the angle of each ejection hole to the water wheel. Therefore, the rotational efficiency of the water wheel was low and the power generating efficiency was also low.
In view of the above problem, a first object of the invention is to provide a small-sized hydroelectric power generating apparatus constructed so that in order to effectively generate electric power with a small amount of flowing water, detent torque between the a rotor magnet and a pole tooth is kept low, and the loss of magnetic fluxes effective to power generation is small.
In view of the above problem, a second object of the invention is to provide a small-sized hydroelectric power generating apparatus which has such structure that an ejection hole for efficiently ejecting water to the water wheel can be formed without using many split molds and a complicated machining method such as turn-separation, and which can improve rotational efficiency of the water wheel and also power generating efficiency.
A small-sized hydroelectric power generating apparatus according to the invention includes a body case having a fluid passage, a water wheel that is provided at the fluid passage and rotates with passing of the fluid having the predetermined flowing amount, and a rotator that is coupled to this water wheel, rotates with the water wheel, and is used as a rotor portion arranged opposed to a stator portion, in which this rotor portion is relatively rotated in relation to the above stator portion with the passing of the fluid thereby to generate electric power. This small-sized hydroelectric power generating apparatus is provided in that the stator portion has pole teeth that are arranged in the circumferential direction at regular intervals so as to be opposed to the peripheral surface of a rotor magnet of the rotor portion, and a circumferential gap between the adjacent pole teeth is set to 1.5 times or less the size of a radial gap between each pole tooth and the rotor magnet.
As described above, the gap between the pole teeth is set to 1.5 times or less the size of the gap between each pole tooth and the rotor magnet, whereby the gap between the pole teeth becomes much narrower, so that detent torque becomes small, the water wheel and the rotator can be rotated smoothly even with a small amount of flowing water, and power generation can be efficiently performed. According to the above-mentioned structure, without expanding the radial gap between each pole tooth and the rotor magnet, the detent torque can be reduced. Therefore, without reducing the magnetic fluxes effective in rotating the rotor, the rotor can be rotated with the large torque.
Further, according to another aspect of the invention, in the afore-mentioned small-sized hydroelectric power generating apparatus, the stator portion is composed of two phases that are not in the phase. Therefore, the detent torque becomes smaller, and the water wheel and the rotator can be rotated more smoothly.
According to another aspect of the invention, in the above-mentioned small-sized hydroelectric power generating apparatus, magnetic insulation is applied between adjacent stator cores of the two-phases stator portion. Therefore, the stator portions of the respective phases cancel the detent torque of each other, their detent torque approximate a sine waveform, and the detent torque becomes smaller. Therefore, the water wheel and the rotator can be rotated more smoothly.
According to another aspect of the invention, in the above-mentioned small-sized hydroelectric power generating apparatus, two stator cases are provided so as to respectively cover the two-phases stator portion, and these two stator cases are magnetically connected. Therefore, the detent torque cancellation between the magnetically insulated stator cores becomes stronger, so that the detent torque can be reduced more.
According to another aspect of the invention, in the above-mentioned small-sized hydroelectric power generating apparatus, each of the pole teeth is formed nearly in the shape of a trapezoid. Therefore, the detent torque becomes smaller and the effective magnetic fluxes for rotating the rotor become larger.
According to another aspect of the invention, a small-sized hydroelectric power generating apparatus includes a body case having a fluid passage, a water wheel that is provided at the fluid passage and rotates with passing of the fluid having the predetermined flowing amount, and a rotator that is coupled to this water wheel, rotates with the water wheel, and is used as a rotor portion arranged opposed to a stator portion, in which this rotor portion is relatively rotated in relation to the above stator portion with the passing of the fluid thereby to generate electric power. This small-sized hydroelectric power generating apparatus is provided in that: a support member for holding one end of a shaft for supporting rotation of the water wheel is provided for the body case; a water spouting portion having an ejection hole from which the fluid is blown on vanes of the water wheel with the flowing amount throttled is provided for the fluid passage; and at least a part of this water spouting portion is provided integrally with the above body case.
According to the above aspect, the water spouting portion which spouts the fluid on the vanes of the water wheel and surrounds the water wheel is formed integrally with the body case, and the support member for holding one end of the shaft for supporting rotation of the water wheel is provided for the body case. Therefore, the positional accuracy among the water-spouting portion that surrounds the water wheel, the ejection hole formed in the water-spouting portion, and the shaft for supporting the rotation of the water wheel becomes good.
Accordingly, the rotational accuracy of the water wheel in relation to the water-spouting portion becomes good, so that the distance as gap between the peripheral end of the water wheel and the inner wall of the water-spouting portion can be narrowed. As a result, the fluid blown out from the ejection hole can be efficiently dashed on the water wheel, and the water wheel can be efficiently rotated.
Further, according to another aspect of the invention, a small-sized hydroelectric power generating apparatus includes a body case having a fluid passage, a water wheel that is provided at the fluid passage and rotates with passing of the fluid having the predetermined flowing amount, and a rotator that is coupled to this water wheel, rotates with the water wheel, and is used as a rotor portion arranged opposed to a stator portion, in which this rotor portion is relatively rotated in relation to the stator portion with the passing of the fluid thereby to generate electric power. This small-sized hydroelectric power generating apparatus is provided in that: a water spouting portion having an ejection hole from which the fluid is blown on vanes of the water wheel with the flowing amount throttled is provided for the fluid passage; the ejection hole is so constituted as to be opened in the axial direction of a shaft; and this opened portion is closed by another member thereby to form the ejection hole.
According to the above aspect, one axial side of the ejection hole of the water-spouting portion is opened and this opened portion is pushed from the other side. Therefore, such the constitution that the number of the ejections holes of the water spouting portion is set to three, four, or more and the ejection holes are orthogonally opposed to the vane portions of the water wheel in order to heighten the rotational efficiency of the water wheel can be formed by a simple bi-directional split mold. Accordingly, a small-sized hydroelectric power generating apparatus can be obtained, which can be manufactured at a low mold cost and has the water-spouting portion that can blow the fluid on the water wheel efficiently. Further, the water-spouting portion may be formed integrally with the body case, or may be composed of another member and incorporated into the body case.
According to another aspect of the invention, in the above-mentioned small-sized hydroelectric power generating apparatus, the water spouting portion is defined by plural walls formed integrally with the body case and a cover put on leading ends of these walls, and the ejection hole is opened to the cover side and covered with this cover thereby to form the ejection hole. Therefore, a small-sized hydroelectric power generating apparatus can be manufactured at a lower mold cost, which has the water spouting portion having such the constitution that the number of the ejections holes of the water spouting portion is set to three, four, or more and the ejection holes are orthogonally opposed to the vane portions of the water wheel in order to heighten the rotational efficiency of the water wheel.
Further, according to another aspect of the invention, in each of the above-mentioned small-sized hydroelectric power generating apparatuses, a plurality of the ejection holes are provided in the circumferential direction nearly uniformly, and a slope for suitably distributing the flowing amount from the inlet side of the fluid passage to each ejection hole is formed at the peripheral portion of the water spouting portion. Therefore, the water ejected from each ejection hole to the vane portion of the water wheel becomes uniform and the suitable amount of water is ejected, so that the rotational efficiency of the water wheel further improves.
Further, according to another aspect of the invention, in each of the above-mentioned small-sized hydroelectric power generating apparatuses, a cap-shaped case is fitted to the body case thereby to form an inner space; the rotator is provided in this inner space and this inner space and the stator portion are separated from each other; a recess portion is provided for a fitting portion of the body case to the cap-shaped case; an opposing wall opposed to an inner wall of the recess portion is provided for a fitting portion of the cap-shaped case to body case; when the cap-shaped case is fitted into body case while it is being pressed against body case, a ring-shaped elastic seal member is provided, which is held between the opposing wall and the inner wall of the recess portion in the direction orthogonal to its fitting direction; and supporting members that respectively support both ends of the shaft for supporting the rotator are provided for the body case and the cap-shaped case.
According to the above aspect, after the body case and the cap-shaped case were united, the elastic seal member is not pressed in the fitting direction but receives the pressing force from the both cases in the direction orthogonal to the fitting direction. Therefore, the both cases do not have disadvantage that flotation is produced by elastic repulsive power of the elastic seal member and the positional relation in the fitting direction changes with the passage of time. Accordingly, the positional relation between the shaft supporting members respectively provided for the both cases becomes better.